Frederick III, Elector Palatine

Frederick III of Simmern, the Pious, Elector Palatine of the Rhine (14 February 1515 – 16 October 1576) was a ruler from the house of Wittelsbach, specifically the cadet branch of Palatinate-Simmern-Sponheim. He was a son of John II of Simmern and inherited the Palatinate from the childless Elector Otto-Henry, Elector Palatine (Ottheinrich) in 1559. He was a devout convert to Calvinism, and made the Reformed confession the official religion of his domain by overseeing the composition and promulgation of the Heidelberg Catechism. His support of Calvinism gave the German Reformed movement a foothold within the Holy Roman Empire.